Rivet



Mmhzz 1945. A, s MULLGARDT 2,372,222

RIVET Filed Nov. l2, 1942 Patented Mar. 27, 19.45

RIVET Alexander S. Mullgardt, Los Angeles, Calif., as-

signor to Cherry Rivet Company, Los Angeles, Calif., `a corporation of California Application November 2, 1942, Serial No. 464,319

9 Claims. (Cl. 85-40) This invention relates to a type of rivet which is capable oi.' installation in an opening for the rivet in the parts to be riveted, and which is accessible from only one side. Such rivets generally include a body member having a head and shank, the shank being of sleeve form, and carried on a stem. In performing the riveting op. eration the assembled ybody member of the rivet and the stem, are inserted in the opening to be riveted, and while the outer head of the rivet is held against the plates, the stem 'is forcibly pulled outwardly. The inner end 'of the stem is provided with an upsetting head that swages or heads the inner end of the shank over the edge of the hole.54 This type of rivet is used largely in construction work necessitating the use of a great number of rivets; and hence it is desirable to providea lconstruction for the rivet, which will enable the rivets to be putin place and riveted with rapidity. In order to facilitate the insertion of the rivets quickly in the openings to be riveted, it is necessaryl to provide a sufilcient clearance between the shank of the rivet and the edge ofthe aligning openings.

In rivetingi two parts such as two plates together, it is necessary. of course, to have the two plates pressed tightly together whenl the riveting operation occurs. One of the objects of this invention is to provide a simple method for accomplishing this through the agency of the rivet itself, and also for expanding the shank of the novel parts and combination of parts to be described hereinafter, all of which contribute to produce an eilicient rivet, and riveting method.

A preferredembodiment of the invention is 'described in the following specification, while the broad scope of. the invention is pointed out in the appended claims. Inthe drawing:

Fig. 1 is a vertical section taken through twov superposed plates, and illustrating a rivet embodying this invention, set in place ready to be riveted. This view also indicates a riveting tool portion broken away to illustrate a detail of the construction.

Fig.3 is a View lsimilar to Fig. 2, but illustrating the second stage of. the riveting operation in which means on the stem operates to start the upsetting of the inner end of the shank.

Fig. 4 is a view similar to Fig. 3, but illustrating the riveting operation completed and with the upper end of the stem broken oi so as to'leave rivet so that it completely fills the opening in which the rivet is applied. The inventionalso includes the novel features of the rivet that is employed` for effecting these objects.

A further object of the invention is to provide such a rivet with means to insure an effective mushrooming or expansion of the inner end of the shank so as to provide an eiiicient shoulder projecting over the edge of the opening at the inner and inaccessible side of the riveted plates.

A further object of the invention is to provide a stem of such a rivet assembly with means that will operate in the rst vpart of the upsetting movement -of the stem, vtc exert a force to hold the plates together, by commencing with an outward or expanding movement at theinner end of the shank; also to give such means a form which will enable it to cooperate with the upsetting head at the inner end of the stem, to produce an efficient upset head at the inner end of the rivet.

Further objects of the invention will appear hereinafter.

The invention consists in the novel method and the inner portion of the stem tightly held within the shank. This view illustrates the presence of a more effective holding shoulder at the inner end of the shank, to project over the edge of the riveted opening.

Fig. 5 is a side elevation and partial section Aillustrating a modifiedembodiment of the rivet in which a collar on the stem is not formed integrally with the stem, asin the' embodiment of the invention illustrated in Figs. 2 to 4. In this view the upper portion of the stem is broken away, and the collar is illustrated in fulllines in its normal position. The collar is also indicated inl dotted lines in a relatively shifted position which it assumes during the riveting operation.

` Referring-particularly to Figs. 2 to 4 inclusive, in practicing the invention I employ a rivet assembly including a rivet body having a head l and an integral shank 2, which is of sleeve'forxn so that it present-s a bore received on a stem 3 that fits in the bore. This stem lpreferably ts friction-tight in the bore, so that the stem will f maintain itself withinthe rivet body in substantially the relation indicated in Fig. 2. In forming this rivet assembly, the pulling head I at the outer end ofthe stem is upset on the stem after the rivet body is slid over the outer end of the stem, that is to say, on the end of the stem that is remote from the upsetting head 5. Adjacent the upsetting head 5 the stem is preferably formed with a neck 6 of slightly larger diameter than the relatively small body portion of the stem 3 as viewedin Fig. 2, a slight tapered shoulder 'l being formed at the junction of the two differing diameters. Adjacent the inner end of the shank 2 the stem 3 is provided with a collar 8, which may be made integral with the stem as illustrated in Fig. 2, or which may be a separate piece from the stem, as will be described hereinafter. This collar 8 is preferably of substantially the same diameter as the upsetting head 5, and this diameter is as large as possible, that is to say, the largest diameter that can be quickly passed through the opening 9 in the superposed plates I0, or similar parts that are to be riveted together.

InFig. 2 considerable clearance is indicated between the shank and the edge of the opening,

but in practice, of course, this clearance would be y slight, though it should be suicient to enable the rivets to be set in place quickly for riveting. The outer side of the collar- 8, that is to say, the upper face as viewed in Fig. 2, s preferably an inclined face II. After setting the rivet in place as illustrated in Fig. 2, a riveting device I2 is employed to effect the upsetting of the shank 2 by forcibly pulling the stem 3 outwardly. It presents an inner sleeve I2a to which cam levers I2b are pivotally attached. This sleeve I2a can be attached to the head 4, and when the levers I2b are pressed forcibly downward, theircams pull the sleeve I2a upwardly; at the same time, the cam levers B2b bear against the body of the tool I2 and hold the outer head I of the rivet in place and tightly against the upper face of the upper or outer plate I0. The upward pull on the stem 3, of course, immediately brings the collar 8 into contact with the end of the shank 2, and this collar, particularly by reason of its inclined face II, causes an expansion of the inner end of the shank in some such manner as illustrated in Fig. 3, causingthe lower end of the shank to assume `a more or less -mushroom form, and thereby squeeze plates I 0 tightly together. Soon after the rivet shank assumes the shape indicated in Fig. 3, aV continued pull on stem 3 will shear the collar 8 from the stem, permitting further upward movement of the stem. This movement will cause the inclined shoulder l to ride up through the sheared opening in the collar, and will cause the slightly enlarged neck 6 to move through the collar and up through the bore of the shank.- Asthe enlarged neck 8 moves up into the shank 2 of the sleeve, it causes an expansion of the shank so that it will tightly illl the rivet opening 9. This is illustrated in Fig. 4 which shows the relation of all the parts'when the riveting operation is completed. As the outward or upward movement `oi the stem continues toward the final condition indicated in Fig. 4, the collar 8 will seat itself on the upper face or shoulder 5a of the upsetting head 5. This shoulder will then exert upward pressure upon the collar 8, pulling the same tightly into the expanded and mushroomed end of the sleeve. This will cause a further mushrooming of the end of the shank, and shouldform a more substantial shoulder I3 projecting under the inner edge of the opening as illustrated in Fig. 4. The inclination of the inclined face II, of course, assists in forming this shoulder I3 because it will develop an expanding force composed of stresses in the mushroomed head acting along lines normal to the conical face of the collar.

If desired, the collar, such as the collar 8, need not be made integral with the stem; and in Fig. 5 I illustrate a construction in which the collar I4 is formed as a separate piece from the stem I5. This collar would be very tight, however, on the stem-sufficiently tight to insure that When it moves relatively back onto the tapered shoulder IB, it will operate to enter the inner end of the shank and start the upsetting operation much like the operation of the other collar 8, as illustrated in Fig. 3.

' In the operation of both of these forms of this invention, the enlarged neck 8, and the enlarged neck I1 of Fig. 5, develop a slight expansion of the collar, as this enlarged diameter passes up through the collar. This develops an effective mushrooming and upsetting of the inner end of the shank.

Although I have illustrated this rivet assembly as having a pulling head 4 to enable it to cooperate with a riveting tool such as illustrated in Fig. 1, it, should be understood that other riveting tools are employed for use with this type of rivet, in which two jaws are employed that clamp the side of the stem 3. If the rivet is to be used with such a tool, it will be unnecessary, of course, to form any pulling head such as the pulling head 4 on the stem. f

It is also not essential to provide the upsetting head 5 at the inner end of the rivet, if the riveting gun employed has a limit stop to prevent pulling the rivet stem too far. The inner head 5, however, does provide a stop for the collar to prevent the stem passing out of the collar.

After the upsetting operation is completed, the outer portion of the stem is cut olf or broken oi at the shoulder 1 which, in practice, would be then located substantially flush with the outer face of the outer rivet head I.

Many other embodiments of the invention may be resorted to without departing from the spiri-t of the invention.

What I claim is: Y

1. In an upsettable rivet assembly for riveting plates'in an opening for the rivet accessible from o'nly one side, the combination of a rivet body having a sleeve-form shank for fitting into the opening, a stern carried in the bore of the sleeve 'and substantially illling the same, and having an upsetting head at its inner end forming a shoulder, and a collar located on the stem at a point removed from the upsetting head and between lthe upsetting head and the shank end, for engaging the shank before the upsetting head commences to act, said collar having a conical face with its larger diameter disposed toward the upsetting head, operating to engage the end face of the shank and force the end face of the shank outwardly to start the upsetting movement, and operating to seat substantially against the upsetting head at the termination of the upsetting movement of the stem.

2. In an upsettable rivet assembly for riveting plates together through an opening accessible from only one side, the combination of a rivet body having a sleeve-form shank for fitting into the opening through the plates, and having a bore of substantially uniform diameter, a stem having a body portion o`f relatively small uniform diameter iltting closely within the bore of the shank and having a neck of relatively larger diameter outside of the shank lying adjacent the innerendottbe'shanhandaeollarcarrtedon said stem, capable of oilering considerable resistance to movement along` the stem,- said collar having a substantially conical lace with its larger diameterV located toward the inner end of said stem, and operating when the stem is pulled. to upset the shank and form a shoulder extending over the edge of the said opening while said eollarmaintains its position on the stem, and so that the tension in the rivet stem exerted at the said shoulder pulls the said plates iirmly together; said collar operating thereafter when the force pulling the stem is increased to overcome the resistance of said collar and move the saine relatively rearwardly on the stem and ontothe said lrelatively larger neck, said-neck then operating to expand the said collar and thereby develop a further upsetting effect at said shoulder; said neck operating to-pass into the said shank and fitting closely into the bore of the shank, saidstem having an upsetting head at its inner end. and a collar tight on the stem between the upsetting head and the said shank, operating when the stem is pulled outwardly, to force the extreme end of the shank outwardly beyond the edge of the opening to start the forming of a head on the shank, and thereafter operating to slip back relatively on the stem to rest upon the upsetting head, and cooperating thereafter with the `upsetting .head to complete the forming ot an upset head on the inner end of the tubular shank.

'4. An upsettable rivet assembly according to claim 3, in which the stem is provided with a neck of enlarged diameter adjacent the upsetting head, operating rst to expand the collarl and thereafter to expand the shank to iill the,

rivet opening in the plates.

5. An upsettable rivet assembly according to claim 3, in which the said collar on the stem is formed integrally with the stem, said collar operating to become sheared from the stem by the pressure of the collar against the end of the shank.

6. Arivet assembly comprising: a rivet body having a tubular bore, a stem slidable in the` bore of-said rivet body and having an enlarged porupsetting of saidnvet body.

7. In a blind rivet assembly wherein a pulling stem' is drawn through a tubular rivet, to force an expander mandrel into said rivet until limited by an upsetting head adapted to clinch said rivet by uptting the extended end of said rivet, the combination ot an upset-initiating means comprising: a ilange fixed on said pulling stem and positioned to engage said rivet, the connection between said ilange and stem being capable of yielding after said ilange eilects an initial upset of said rivet, thereupon said ilange slides over said mandrel and against said head.

' 8. In a blind rivet assembly wherein a pulling stem is drawn through a tubular rivet until limited by an expander mandrel and upsetting head, the latter offering suillcient resistance upon upsetting said rivet thatvsaid stem may be pulled in two, the combination of: an upset-initiating flange positioned on said stem to engage said rivet prior to said mandrel and head and eiect an initial upset, the connection between said ilange and said stem being arranged to yield upon such initial upset of said rivet whereupon said flange is ,adapted to slide over saidmandrel and y of said rivet body, an expander mandrel adapted to be drawninto said body by said shank portion,

and an upsetting head at one end o! said mandrel forming therewith a stop shoulder; and an upsetinitiating ilange on said shank portion, said iiange being yieldable when forced against said rivet body suillciently to eilect an initial upset-expansion ofsaid body and thereupon become slidable on said shank portion and mandrel until limited by said stop shoulder.

S. MULLGARDT. 

